The collection and transportation of food substances is a large and important activity in which technology of systems and materials plays an ever increasing role. Foods such as fruits and vegetables are often grown at great distances from urban population centers and must be packaged and shipped to market via air, land, rail or water transportation media. While each transportation system offers some material or economic advantage, all systems would benefit substantially if they could overcome the following problems:
1. Reduce weight of the containers, since weight reductions generally translate to energy cost reductions or permit larger "pay" loads; PA1 2. Reduce temperature variations, since excessive heating or cooling damages produce such as citrus fruits or vegetables; PA1 3. Reduce vibrations and impact damage to produce such as fruits or vegetables, since these cause "bruises" and spoilage, and breakage in the case of fragile articles; PA1 4. Eliminate size limitations or restrictions which may be dictated by a material of construction or a method of fabricating containers; and PA1 5. Maintain wet strength of container.
Prior art has solved some of the previously cited problems in various ways. For example, woven baskets made of natural cellulosic products have served as collection, storage and shipping containers from time immemorial and are still excellent containers. This type of container solves portions of problems 1 and 4 cited above, but is not effective for problems 2, 3 and 5.
Steel or other metallic wire baskets have also been used, especially as bottle carrier containers, but these containers are generally effective only in solving problems 4 and 5 above.
Paper, such as cardboard, corrugated cardboard, etc. has been especially effective against problems 1, 2 and 4 but wet strength (5) is deficient.
Plastics, based on a variety of synthetic polymers, have generally been more effective than metal and wire mesh, but are usually more costly than wood or paper based containers.
U.S. Pat. No. 3,426,933, J. W. Stecke, describes field boxes for shipping citrus fruits of premolded plastic bottom panels or side members which are immune to rotting, and includes wooden end panels and partition members.
French Pat. No. 1,540,455, P. Ricour, shows a design for end pieces of a crate which may be molded from synthetic resin or formed of metal. The end piece has an aperture which serves as a handle.
French Pat. No. 2,090,030 discloses molded monolithic packing tray for fruits and vegetables, made of expanded polystyrene. This tray has separate molded compartments such as foam egg cartons.
U.S. Pat. No. 3,834,574, I. Nadeshima, et al. describes a casing for transporting bottles wherein the outer member is made of wood, and the inner member of foamed plastic, the entire assembly unitized by screws, steel bands, or adhesives.